package com.TZULibrary.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.TZULibrary.dto.Result;
import com.TZULibrary.entity.SeckillVoucher;
import com.TZULibrary.entity.VoucherOrder;
import com.TZULibrary.mapper.VoucherOrderMapper;
import com.TZULibrary.service.ISeckillVoucherService;
import com.TZULibrary.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.TZULibrary.utils.RedisIdWorker;
import com.TZULibrary.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    String queueName="stream.orders";
    private class VoucherOrderHandler implements Runnable{
        @Override
        public void run() {
            while (true){
                try {
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    if (list==null||list.isEmpty()){
                        continue;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    handleVoucherOrder(voucherOrder);
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                }catch (Exception e){
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }
    }

    private void handlePendingList() {
        while (true){
            try {
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1"),
                        StreamReadOptions.empty().count(1),
                        StreamOffset.create(queueName, ReadOffset.from("0"))
                );
                if (list==null||list.isEmpty()){
                    break;
                }
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> values = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                handleVoucherOrder(voucherOrder);
                stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
            }catch (Exception e){
                log.error("处理pending-list订单异常",e);
                try {
                    Thread.sleep(20);
                } catch (InterruptedException ex) {
                    throw new RuntimeException(ex);
                }
            }
        }
    }

//    private BlockingQueue<VoucherOrder> orderTasks=new ArrayBlockingQueue<>(1024*1024);
//
//    private class VoucherOrderHandler implements Runnable{
//        @Override
//        public void run() {
//            while (true){
//                try {
//                    VoucherOrder voucherOrder=orderTasks.take();
//                    handleVoucherOrder(voucherOrder);
//                }catch (Exception e){
//                    log.error("处理订单异常",e);
//                }
//            }
//        }
//    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        if (!isLock){
            log.error("不允许重复下单");
            return;
        }
        try {
            proxy.createVoucherOrder(voucherOrder);
        }finally {
            lock.unlock();
        }
    }

    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        long orderId= redisIdWorker.nextId("order");
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString(),String.valueOf(orderId));
        int r=result.intValue();
        if (r!=0){
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        return Result.ok(orderId);
    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        Long userId = UserHolder.getUser().getId();
//        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString());
//        int r=result.intValue();
//        if (r!=0){
//            return Result.fail(r==1?"库存不足":"不能重复下单");
//        }
//        VoucherOrder voucherOrder = new VoucherOrder();
//        long orderId= redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        voucherOrder.setVoucherId(voucherId);
//        voucherOrder.setUserId(userId);
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        orderTasks.add(voucherOrder);
//        return Result.ok(orderId);
//    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())||voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀不在时间范围内！");
//        }
//        if(voucher.getStock()<1){
//            return Result.fail("库存不足！");
//        }
//        Long userId = UserHolder.getUser().getId();
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//
//        boolean isLock = lock.tryLock();
//        if (!isLock){
//            return Result.fail("不允许重复下单");
//        }
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            lock.unlock();
//        }
//    }

    @Transactional
    @Override
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        int count = query().eq("user_id",userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count>0){
            log.error("用户已经购买过一次！");
            return;
        }
        UpdateWrapper<SeckillVoucher> updateWrapper = new UpdateWrapper<>();
        updateWrapper.setSql("stock=stock-1").eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0);
        boolean success = seckillVoucherService.update(updateWrapper);
        if (!success){
            log.error("库存不足!");
            return;
        }
        save(voucherOrder);
    }
}
